Insulated rail joint



1967 w. R. HAMILTON, JR, 3,335,954

INSULATED RAIL JOINT Filed March 17, 1966 F FIG. 3.

'INVENTOR WILLIAM R. HAMILTOMJR.

ATTORNEY I United States Patent 3,335,954 INSULATED RAIL JOINT WilliamR. Hamilton, Jr., Fairfield, Conn., assignor to Poor & Company, Chicago,111., a corporation of Delaware Filed Mar. 17, 1966, Ser. No. 535,206Claims. (Cl. 238-243) ABSTRACT OF THE DISCLOSURE An insulated rail jointcomprising a plurality of metal strips bonded together to form a coreand encapsulated with a non-conductive coating.

This invention relates to rail joints, and more particularly to jointbars of the insulated type which may be assembled to meet a selectedrail section and then completed ready for use as individual units, eventhough such units may be, for production reasons, made in apparatusproducing more than one complete unit at a given time.

As well known, now and heretofore, it has been the custom to manufacturebars for insulated joints in a rolling mill according to rigidspecifications. This practice requires turning up and maintainingoccasionally used expensive roll sets whose costs are reflected in theindividual units primarily because the number of insulated bars are sorelatively few as compared with standard bars used merely to connectconductively adjoining rails in jointed track. The bars rolled in longsections are cut to thelength desired, usually 24" or 36", andsubsequently have bolt holes punched in their webs after re-heating.

Accordingly, one of the objects of the present invention is to provide aunit including a prefabricated laminated metal core which may be changedas to size to fit different size rails and then encapsulated orotherwise enclosed in an appropriate synthetic plastic coating or cover,to suit a wide range of particular individual specifications andinstallation needs. Other means of enclosing the core may comprise, forexample, dipping, wrapping with a preimpregnated plastic material, orwinding with a plastic filament.

Another object of the invention is to provide a novel metallic coreincluding a plurality of special relatively thin metal strips, and alsospecial arrangements thereof, to accommodate insulated bolt holes, andprovide maximum resistance to bolt pressures incident to installing thebars in place.

A further object is to combine a plurality of thin strips into a corehaving upper and lower cap pieces whose rail facing portions areinclined either 13 or 14 to fit rails above and below 100# to the yard.

With these and other objects in view which will more readily appear asthe nature of the invention is better understood, the invention consistsin the novel construction, combination, and arrangement of partshereinafter more fully described, illustrated, and claimed.

A preferred and practical embodiment of the invention is shown in theaccompanying drawings, in which:

FIG. 1 is a vertical cross-sectional view of a joint bar including theimprovements of the present invention and shown as it is initiallyfitted in the fishing space of the rail ends of the joint to beinsulated, as in signal track.

FIG. 2 is an enlarged detail side elevation showing the metallic stripsstacked one upon the other and also as they would appear, for example,at the location of a bolt hole.

FIG. 3 is a detail cross-sectional view of the bolt receiving ferrule.

FIG. 4 is a detail perspective view showing the stacked strips with oneform of interlocking rib and groove arrangement.

FIG. 5 is a similar detail perspective view showing strips with adifferent form of interlocking formation, not only to facilitateassembly, but to increase resistance to bolt pressure.

Similar reference characters designate corresponding parts throughoutthe several figures of the drawings.

Referring first to FIG. 1, it will be observed that the rail R istypical of a section with which the present invention will be used.

The fabricated joint bar is designated generally as A and includes alaminated core B having at appropriate spaced locations, bolt receivingferrules C. As shown in FIG. 1, the core B and ferrules C areencapsulated in a coating of synthetic insulating material D such as,for example, polyurethane, which covers all of the exposed surfaces ofthe bar.

The laminated core B includes a series of superimposed relatively thinflat strips 1 whose wide mating side surfaces are bonded together by asynthetic adhesive such as, for example, a thermosetting resin of theepoxy type designated generally as la. This bonding of the strips orleaves together eliminates motion between them in bending by putting theadhesive layer into shear.

' As will be seen from FIG. 1, the top and bottom cap strips 2 and 3have their outer face portions inclined at an angle corresponding to anangle of the fishing spaces at the head and foot of the bar. In FIG. 1these faces are designated respectively as 2a and 3a.

The metal strips 1 may be of any desired length to permit handling andmanipulation with reference to the bolthole locations. That is to say,the stacked, or otherwise placed, metallic strips 1 may be assembled inrelation to the ferrule C as shown in FIG. 2. The voids or interspaceoccurring between the ends of strip 1 and the ferrule C are filled witha synthetic resinous bonding agent to not only secure them in place butalso to preserve the full insulating qualities of the bar.

The thickness of a strip 1 is preferably, for example, within the rangeof approximately to A". A strip whose thickness is less than has atendency to lose its structural quality of being able to stand byitself. A strip whose thickness is greater than A" would leave too muchclearance around the bolt hole and also would be difficult to laminateto the proper height.

As appears from FIGS. 1 and 3, the ferrule C includes as internalmetallic thimble or sleeve 5 externally coated with an insulatingmaterial 6 preferably, but not necessarily, of the same type as thebonding material In.

Referring to FIG. 4, it will be seen that the core forming strips 7 areprovided with offset rib portions 8 which mate with each other and servefurther to lock the superimposed strips against relative transverse orhorizontal movement even though they are bonded together at theircontacting faces.

FIG. 5 is a view illustrating a-diiferent form of interlock between thestrips 9. In this case, the interlock rib and groove is of substantiallyZ-shaped or stepped formation with the crest 10 of the interlockoccurring in a manner to further resist bolt pressure even though thestrips are adhesively bonded together.

In addition to the means shown in FIGURES 4 and 5 for mechanicallyinterlocking the stacked strips, the fiat strips shown in FIGURES 1 and2 may be provided with a plurality of spaced holes which are alignedwhen the strips are stacked, and pins or pegs are then inserted throughthe aligned openings to provide an additional locking feature.

From the foregoing, it will now be understood that the internal core Bis composed of a plurality of superimposed strips made fast together bybonding and/or having mechanically interlocked portions which alsoprevent lateral displacement, while the outer faces of the top andbottom members are inclined to insure that the entire assembly, both thestrips and cover, readily match the angle of the rail fishing surfaces.

A further distinctive feature of the invention is to stack or place flatmetal strips so that their relatively narrow side-edge portionseliectively resist bending under bolt pressure, while the relativelyflat side portions are bonded and/or interlocked relative to each otherand hold the bolt ferrule C in position, to enable the encapsulatedmaterial to be readily applied.

The principle of using thin strips rather than thicker sections, is thatby changing the length of each piece in the area of the bolt holes, itis possible to vary their spacing without involving the use of anotherset of tools or materials.

I claim:

1. An insulated rail joint bar, comprising in combination, a coreincluding a plurality of metal strips having their narrow side edgesdisposed toward the outer and inner faces of the bar and at right anglesto the bolting forces to be applied to the bar,

said metal strips extending the entire length of the core and providedwith intermediate layers of adhesive material bonding all juxtaposedsurfaces of said strips into a unitary core,

ferrules disposed at spaced intervals transversely of the laminated coreto receive bolts and having external insulating sleeves,

and an insulation cover surrounding said core and ferrules.

2. An insulated rail joint bar according to claim 1, wherein the top andmost of said strips have their upper and lower faces formed atsubstantially an angle in the range of 13 to 14 to insure the overlyinginsulation cover fitting the related opposed faces of the rail fishing.

3. An insulated rail joint bar according toclaim 1, wherein the laminaeof said core have mating interfitting portions parallel with at leastone end of the laminae to assume shearing stresses in the core imposedby bolt pressure.

4. An insulated rail joint tion,

a laminated metal core, ferrules disposed at spaced intervalstransversely of the laminated core to receive bolts and having externalinsulating sleeves, the laminae of said core have substantially Z-shapedmedial ribs extending longitudinally thereof with the V-shaped pocket ofone rib receiving the mating shoulder of the adjacent rib, thereby toabsorb shearing stress in the core by pressures exerted in a horizontalplane by the bolts, and an insulation cover surrounding said core andferrules. '5. An insulated rail joint bar, comprising in combination,

a laminated metal core, ferrules disposed at spaced intervalstransversely of the laminated core to receive bolts and having externalinsulating sleeves, an insulation cover surrounding said core andferrules, and the interspace between the laminae and the adjacentferrules is filled with nonconductive bonding material.

bar, comprising, in combina- References Cited UNITED STATES PATENTS2,444,558 6/ 1948 Miller i 238-260 3,071,325 1/1963 Douglas 238-244FOREIGN PATENTS 919,548 2/ 1963 Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

R. A. BERTSCH, Assistant Examiner.

